Table Of ContentBy the Same Author
Boivin, D.B., and A. Shechter. “Light and Melatonin Treatment for Shift Work.”
In Encyclopedia of Sleep, ed. Clete A. Kushida. Amsterdam: Elsevier Press
(forthcoming).
Boivin, D.B., and A. Shechter. “Light Therapy.” In Encyclopedia of the
Neurological Sciences, 2nd edition, eds. M.J. Aminof and R.B. Daroff.
Amsterdam: Elsevier Press (forthcoming).
Boivin, D.B. “Jet lag.” In Encyclopedia of the Neurosciences, ed. Kate
Miklaszewska-Gorczyca. Amsterdam: Elsevier Press (forthcoming).
Boivin, D.B., and P. Boudreau.“Les troubles du sommeil et des rythmes
circadiens.” In Les troubles du sommeil, ed. M. Billard and Y. Dauvilliers.
Paris: Masson, 2011.
Boivin, D.B. “Disturbances of Hormonal Circadian Rhythms in Shift Workers.”
In Neuro—endocrine Correlates of Sleep/Wakefulness, eds. D. P. Cardinali
and S. R. Pandi-Perumal. New York: Springer, 2006.
Boivin, D.B., G.M. Tremblay, and P. Boudreau. Les horaires rotatifs chez les
policiers :étude des approches préventives complémentaires de réduction de
la fatigue. Montreal: Institut de recherche Robert-Sauvé en santé et en
sécurité du travail (IRSST), 2010.
Boivin, D.B., and F.O. James.Prévention par la photothérapie des troubles
d’adaptation au travail de nuit. Montreal: Institut de recherche Robert-Sauvé
en santé et en sécurité du travail (IRSST), 2002.
Boivin, D.B. “Comment réduire les effets négatifs du travail de nuit sur la santé
et la performance ?” Gestion (HEC Montreal) 35, no. 3:47-52, 2010.
I dedicate this book to Johanne, who has always been by my
side, and to Guillaume, my steadfast companion.
To my parents for all the love they gave me.
To Catherine and Christine for their invaluable advice.
Thank you to all my friends for the evenings of wining and
dining.
Thank you to all the employees and enthusiastic students at the
Douglas Institute’s Centre for Study and Treatment of
Circadian Rhythms.
Table of Contents
Sleep and You
Dedication
Contents
Foreword
Introduction
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Conclusion
About the Author
Credits
Foreword
Sleep is a part of everyday life and the subject of familiar expressions — “Good
night,” “Did you sleep well?” — but it’s also a topic we are asking ourselves
more and more questions about. Long a little-explored frontier of the
neurosciences, our understanding of the mechanisms that control sleep has made
remarkable strides in recent decades. Paradoxically, in the same period, a
relatively new behaviour pattern has become widespread in industrialized
societies: partial sleep deprivation that, day after day, lets us work longer hours,
stay up later to amuse ourselves, and increases the time we spend on activities,
right to the limit of what is tolerable. Thanks to artificial light, modern man has
gradually developed this uniquely human behaviour pattern: no other mammal
chronically deprives itself of sleep. Yet while this behaviour pattern is abnormal
in terms of our biology, it is still often admired and envied! Nonetheless, fatigue,
difficulties in concentrating, the feeling of being inefficient and in a bad mood
— the price paid by many for hours stolen from sleep — make us wonder: Is a
manager who boasts about only getting four or five hours of sleep a night a hero
or a fool?
To shed light on this complex and fascinating subject, Diane B. Boivin has
written a rigorous book dealing with ideas on the cutting edge of current
neurological and chronobiological research. In it she explains, in a clear and
easily understandable way, why quality sleep is essential for good mental and
physical health.
Many years ago, I tried to persuade Diane to come and work in my
laboratory at the University of Chicago. In the end, she chose Harvard, where
she made her way flawlessly through a highly charged environment, followed by
a brilliant career at McGill University. The invitation to write the foreword to
her first book written for the general public stems from years of respect,
admiration, and friendly collegiality. It gives me the opportunity to briefly touch
on my “pet subject” — the interactions between endemic sleep debt and the
obesity and diabetes epidemics.
Since we sleep less and less, it’s becoming more and more important to
understand just how disastrous the consequences of inadequate or poor-quality
sleep can be. My laboratory has been focusing on this subject for nearly fifteen
years. Our initial results have encouraged other teams to explore the close
years. Our initial results have encouraged other teams to explore the close
connections between sleep, hormonal regulation, and cardio-metabolic risk. It’s
now well established that insufficient sleep has harmful effects on the hormones
involved in appetite control. Limiting sleep time to four or five hours for less
than a week leads to an appreciable increase in resistance to insulin, a hormone
that is key to regulating glucose and lipids.
Short sleepers do exist and are described as people who manage to function
reasonably well, both biologically and psychologically, on six hours a night or
less, night after night. But these individuals appear to represent less than 10
percent of the population. In reality, many people who say they are short
sleepers need more sleep than they think they do. The overall message of more
than a hundred studies is that most adults need at least seven hours of sleep to
stay biologically and psychologically healthy.
Perhaps in twenty years’ time improvements in our understanding of sleep
will have helped change people’s perceptions, making them see that sleep is as
important as proper nutrition and exercise and that it’s essential to give it the
attention it deserves. This book makes a major contribution and is well
documented using the most up-to-date sources. The author’s straightforward and
lively style makes it a delight to read — and I guarantee it will keep you awake!
Thank you, Diane!
Ève Van Cauter, Ph.D.
Frederick H. Rawson Professor
Sleep, Metabolism and Health Center
The University of Chicago
INTRODUCTION
What Happens in the Bedroom?
Movement is the very essence of life. I love the seasons — snow falling,
melting, and falling again, the alternation of day and night and, of course,
waking and sleeping. The sleep-wake cycle has always intrigued me; it is, after
all, one of our body’s fundamental rhythms, just like our heartbeat or breathing.
When I think about this rhythm and ways to keep it steady and strong into old
age, I find myself dreaming once more of the mythical Fountain of Youth ... A
scientist’s whimsical thoughts aside, sleep is still a fascinating state, full of
mysteries and surprises. This book, not unlike deep-sea diving, is an exploratory
journey into the depths of sleep. I’m offering myself as your guide on what is
nothing less than a journey through its reefs! Then, when the great white shark
of frustrating sleepless nights pounces on you, even though you may have to face
it alone, you will have a better idea of how to fend it off.
Chapter 1 describes what sleep is, what it consists of, and how it’s studied.
The brain works differently depending on whether it’s asleep or awake. The
logic governing sleepers’ behaviour is very different from the logic in control
when they are awake. Activities performed when you are awake will influence
the regions of the brain calling for more rest. Thus, your waking state has an
effect on your sleep. Both are part of a sleep-wake cycle and are influenced by a
biological clock located deep in the centre of the brain. Chapter 2 describes the
biological rhythms called circadian rhythms and the disruptions that affect them.
Sleep, in turn, influences your waking state. In fact, sleeping is essential if you
want to be wide awake and function properly the next day. The older you get,
the more you will appreciate the benefits of sleep and the impact of missing a
few hours. Changes in sleep throughout life are discussed in Chapter 3, where
we’ll see that sleeping well helps us age better. Chapter 4 is devoted to insomnia.
It describes the causes and offers advice to ease the burden.
A lack of sleep causes us to eat during the night, and sleep is closely related
to diet, metabolism, and weight control. The saying “they who sleep forget their
hunger” is true: this is the subject of Chapter 5. Establishing good sleep hygiene
is beneficial for both physical and mental health. Chapter 6 describes sleep
is beneficial for both physical and mental health. Chapter 6 describes sleep
disturbances in various psychiatric and psychological disorders, including
depression. A tendency to sleep that’s too strong and extends into our periods of
activity is known as daytime sleepiness. Chapter 7 deals with this subject and its
clinical management in patients suffering from it. Nighttime breathing problems,
largely responsible for daytime sleepiness, are the subject of Chapter 8. And
sometimes the line between sleeping and waking is so fine that the two become
confused in a borderline state of consciousness. Chapter 9 describes restless
sleep disorders typical of such states, as well as motor problems during sleep.
This book is intended to be both an overview of the latest discoveries about
sleep and a guide to help you sleep better. The hectic rhythm of modern life
often — too often for some (including the author) — leads us to burn the candle
at both ends. We learn very young to “live on credit” by borrowing, day after
day, a few hours a week from the gods of slumber. At first glance, this reserve of
hours seems to be unlimited, even free, and, because we are young, we tolerate
fewer hours of sleep without experiencing repercussions on our performance in
school or in our social life that are too severe. Or at least, so we think! I hope
that reading this book will convince you of the opposite and of the benefits of
sleep, but especially that it will provide you with useful advice. A solid
understanding of what sleep and waking are and what plays a role in disrupting
them is crucial. Remember that the source of the Fountain of Youth is a spring at
the foot of the tree of knowledge. And just like the water from that spring, sleep
too has powers of regeneration.
